Water hammer-ish sound in wall. - DIY Chatroom

filthee · 05-14-2007, 10:49 AM

Greetings all.

I have had a water hammer-ish sound coming from my wall in my townhouse. When the toilets are flushed (with "contents") there is a loud vibration/knock in the upper downstairs wall. It doesn't make the sound if the toilet is flushed with water only. I also tested this with all the water turned off so there was no refilling of the toilet and it still makes the noise.

So I called a plumber out and he rebuilt one of the toilet assemblies which didn't help. He also shut off the main water supply and turned on all the faucets to make sure there wasn't any air trapped in the pipes but that didn't solve the problem. He told me that he'd have to cut part of the wall out to secure the drain pipe and that might solve the problem. I told him I'd get back to him.

So have does anyone have any advice before I start cutting holes in the wall? Is there anything else I should try first? If I do cut holes in the wall, will simply securing the pipe be a real solution, or just half-a55ing it?

Thanks so much for your advice. Sorry for all the questions.

tzzzz216 · 05-14-2007, 01:42 PM

Drain pipe ?? you dont get water hammer from a drain line ! Your water pipes might need to be strap to some backing , there may not be air chambers in the system causing the problem , I've also seen a lose stem washer sound the same way .

filthee · 05-14-2007, 02:47 PM

Quote:

Originally Posted by tzzzz216

Drain pipe ?? you dont get water hammer from a drain line ! Your water pipes might need to be strap to some backing , there may not be air chambers in the system causing the problem , I've also seen a lose stem washer sound the same way .

Can you elaborate on the stem washer? I'm not sure what that is.

I went home at lunch to try a few things and here's what I found. The vibration/noise happens when either of the upstairs toilets are flushed. I tried flushing with the refill valve completely open, partially open and completely closed and the sound persists. The noise is a bit softer if the valve is completely closed so the toilet can't refill, but the noise is still there. I also tried holding the 'flapper' open in the tank as it was flushing and it didn't help the noise.

The sound/vibration happens at the moment the 'package' in the toilet makes its way down the pipe to (I'm assuming) an angle in the drain and causes a disturbing rumble. When you hear the toilet bowl 'gulp air' on the flush is when the noise happens. This is why I think it doesn't sound so loud when there isn't a package in the bowl. There is no air pocket being pulled down with the package and that could be causing the rumble.

Anyhow, anyone else have any ideas?

Thanks!

KUIPORNG · 05-14-2007, 03:59 PM

this is so strange... I think you can try different packages to start with... may use some bread, a little bread and then more bread see if it makes any difference....

filthee · 05-14-2007, 04:07 PM

Quote:

Originally Posted by KUI****G

this is so strange... I think you can try different packages to start with... may use some bread, a little bread and then more bread see if it makes any difference....

Thanks for your help!

I've tried it with varying levels of toilet paper. It won't sound up until (what I consider) a normal amount of toilet paper/other stuff is present.

But when it happens it is loud enough to make you cringe.

Also, I should note it's a short, violent vibration. 1 second at the most usually. It goes like this:

Flush > water rushing downline for 3-5 seconds > BRAPRAPBRRAP > water finishes rushing downline.

KUIPORNG · 05-14-2007, 04:10 PM

Would it be possible your vent from the roof/outside is blocked a bit?.... as I assumme you do not have this problem until recently...

filthee · 05-14-2007, 04:21 PM

Quote:

Originally Posted by KUI****G

Would it be possible your vent from the roof/outside is blocked a bit?.... as I assumme you do not have this problem until recently...

Eh... I can check. Is there an air vent for the drain pipes?

I've been noticing this for a few months. The townhouse is about 5 years old.

KUIPORNG · 05-14-2007, 04:31 PM

Yes all drain pipes has to have vent... there may be one or two or more ... normally found at the roof...

well these are base on the information I read from the plumbing book... I am not a plumber... although I install some plumbing in my basement and there is a 2" vent there...

may be you want to wait for the "Ron the Plumber"'s reply for a more information... He is the expect here...

filthee · 05-14-2007, 04:51 PM

Thanks KUI****G!

*beeeeep* Paging Ron the Plumber... *beeeeeep*

Ron The Plumber · 05-14-2007, 08:46 PM

Water hammer is associated with the water lines, something does not sound right, your talking about the toilet, I can't grasp what could be the problem your having, water lines cause hammer, drains don't.

filthee · 05-14-2007, 09:36 PM

Quote:

Originally Posted by Ron The Plumber

Water hammer is associated with the water lines, something does not sound right, your talking about the toilet, I can't grasp what could be the problem your having, water lines cause hammer, drains don't.

Hey Ron. I'm probably misusing the term 'water hammer'. It's really just a loud, short vibration in my downstairs wall/pipes when either upstairs toilet is flushed with something in it. It happens right as the last bit of water/air/package exits the bottom of the toilet bowl and makes the final gulp.

I played around again tonight after work and it did the same whether the shutoff valve was open or closed. Today the plumber installed a new ballcock assembly in one of the terlets and it didn't help either. The only way I can get it to flush without the bang/vibration is to put nothing in the toilet when I flush it.

I read somewhere that possibly my water heater might have some trapped air. But I don't think I should be messing around with that even if it might be a culprit.

Ron The Plumber · 05-14-2007, 10:15 PM

So you are talking about the noise the toilet makes when the bowl water hits the bottom of a flush?

This could be normal operations, have you always noticed this?

filthee · 05-14-2007, 10:24 PM

Quote:

Originally Posted by Ron The Plumber

So you are talking about the noise the toilet makes when the bowl water hits the bottom of a flush?

This could be normal operations, have you always noticed this?

Thanks for your help, Ron.

No, sorry. I'm saying the loud pipe vibration in the downstairs wall happens when the bowl upstairs makes its normal, gulping, flushing sound. The sound I hear in the wall downstairs definitely isn't normal and started doing this fairly recently.

Ron The Plumber · 05-14-2007, 10:27 PM

It's really hard to say what is the problem without hearing it myself.

filthee · 05-14-2007, 10:30 PM

Quote:

Originally Posted by Ron The Plumber

It's really hard to say what

That's what I'm hearing. The plumber told me I should cut a hole in my wall and secure the pipe to a stud. I'd like to explore any other option before coming to that though.

Thank you Ron. You're a gentlemen and a scholar.